1. Field of the Invention
The invention relates to an angle guide plate for the fitting of a rail on a foundation, with a recess serving as a seat for a free end section of a spring arm of a tension clamp to be mounted on the angle guide plate, as long as said tension clamp is located in the pre-assembly position, wherein the recess surrounds the end section by less than half of its circumference.
The invention likewise relates to a system for securing a rail on a foundation, wherein this system comprises an angle guide plate, a W-shaped tension clamp arranged on the angle guide plate, which has at least one spring arm taking effect with its free end section on the rail which is to be secured, and tensioning means for tensioning the tension clamp against the foundation.
2. Description of Related Art
As explained in the brochure published by the Applicant, “Rail securing systems for concrete sleepers—System W 14”, angle guide plates and securing systems of the type under consideration here are used in the securing of rails to a solid foundation, which can be formed, for example, by a concrete sleeper or a concrete plate. The rail to be secured in this situation stands directly on the solid foundation by means of an elastic intermediate layer. To the side, the rail is guided by angle guide plates, a pair of which in each case forms a rail channel which is precisely in place with the course of the track.
With the known securing systems of the type referred to heretofore, the forces introduced via the rail are conducted via the angle guide plate directly into the foundation which carries the rails. For this reason, a shoulder is formed on the individual foundation for each of the angle guide plates, the allocated angle guide plate being supported on said shoulder.
A W-shaped tension clamp is usually mounted on the angle guide plate, which in the complete mounted state presses with the free end sections of its spring arms onto the free upper side of the rail foot of the rail which is to be secured. At a curved support section, facing their free end section in each case and supported on the angle guide plate, the spring arms of the tension clamp merge into a middle loop, which is tensioned against the solid foundation by means of a tension screw.
The U-shaped middle loop of the tension clamp engages around the tension screw. In this situation, its limbs are designed in such a way that, with the tension screw already fitted exerting a reduced clamping force, the tension clamp can be pushed out of a pre-fitting position, in which the free end sections of the spring arms of the tension clamp are seated on a rib extending parallel to the rail which is to be mounted and its support sections are seated on a surface facing the individual shoulder of the solid foundation, into the fitting position, in which the spring arms take effect on the rail foot and the support surfaces of the tension clamp are seated in a recess formed for this purpose into the angle guide plate which recess as a rule is groove-shaped.
In order to ensure the secure seating of the tension clamp in the pre-assembly position, a valley-shaped recess is usually formed on the side facing away from the rail which is to be mounted, into the rib facing the free end sections of the spring arms of the tension clamp. Their overall shape is selected in such a way that the free end sections of the pre-fitted tension clamp are seated in them in positive fit. In this situation, the valley-shaped recess passes at an acute angle into the flat upper side of the rib, which as a rule extends parallel to the standing surface of the angle guide plate facing the foundation. In this way it can be ensured that the tension clamp can only be brought out of its pre-assembly position into the final fitting position by overcoming a certain resistance, over the edge between the valley-shaped recess and the upper side of the rib. Such an unintentional displacement must be prevented, since otherwise the risk arises that the tension clamp will already project into the space intended for the rail before the rail is positioned. This would then impede the proper positioning of the rail.
However, the assembly of the known rail securing systems is rendered elaborate due to the fact that the tension screw which holds the tension clamp in its pre-assembly position must be released by a certain amount in order to be able to move the end sections out of the valley-shaped recess of the rib and push the tension clamp out of the pre-assembly position into the final assembly position. This necessity has proved particularly disadvantageous in practice, because rail fastenings of the type referred to heretofore are, as a rule, assembled in large numbers with the aid of automatic assembly devices. The function of these devices is rendered additionally complicated by the release procedure.